The joints are the most common friction parts of the body when the human body moves. For this reason, the body naturally developed a buffered cartilage to prevent injury on the human body caused by bone friction.
However, under the continuous development of science and technology, human average life-span continues to be extended. But the articular cartilage is gradually worn with the aging of body. It causes the occurrence of degenerative joint disease called osteoarthritis. For patients with knee osteoarthritis in the observation of the X-ray, surgeons can find the uneven of joint surface, narrowed joint cavity and bone spurs. These pathological phenomena will cause the patients to produce pain, swelling, joint deformation, stiffness and other symptoms. This is the inevitable trend of physiological aging, it seems that the older the more likely to encounter the disease.
Taking knee for example, most common treatment of knee osteoarthritis is to implant the artificial joint to replace the knee joint surfaces, but large amount of soft tissue and hard tissue should be removed from the femur, the tibia and the patella to provide the fixation of metal and polyethylene implants. Due to the wear of the polyethylene component, the longevity of the artificial joint replacement is up to twenty years, but often complicated by postoperative infection, osteolysis and bone resorption. Resulting in the possibility of a revision surgery. Furthermore, in early-stage knee osteoarthritis, only the medial articular surface is affected. It is not necessary to replace all articular surface by artificial knee component. High tibial osteotomy is an alternative option for patients with medial knee osteoarthritis.
High tibial osteotomy is performed by a bony cutting plane in the proximal tibia of the knee on the medial side and making an opening wedge by spreading the incision. Finally, the construct is supported by bone plate fixation. Thus the biomechanical axis of the low limb can be corrected. In this procedure, the cartilage and bone stock around the knee are preserved. For the patients with medial knee osteoarthritis, it is a good option for surgical treatment.
The success for high tibial osteotomy relies on an appropriate bone cut including the cutting position, direction, depth, and the spreading height of the incision which are related to the correction angle. This surgery is highly technical demanded. At present, the surgeons perform the procedure based upon preoperative roentgenology images and their experience without any reference or guiding device. Moreover, the condition of genu varum or deformity is different for each patient. The above-mentioned parameters are also different for each patient. A personalized surgical instruments is needed for a better control of the deformity correction.
The prior art of the present invention is TWM536526U. But, there is still room for improvement. For examples, it cannot take a non-invasive assessment of the correction angle when the surgery is performed, it cannot predict whether the angle of the osteotomy device placement is correct, it cannot directly fix the angle of the osteotomy device placement, it may produce an over-cutting phenomenon when starting to cut. The inventor of the present invention has further expanded its function and improved many of the techniques present in the prior art. Therefore, the inventor developed the osteotomy device with an extracorporeal alignment component, the expansion of the function and improvement of the technology will be described in detail in the specification.